Transformable device and method of manufacturing the same

ABSTRACT

A transformable device is provided. The transformable device includes an electro-active layer. A first electrode is disposed at a lower portion inside the electro-active layer. A second electrode is disposed at an upper portion inside the electro-active layer. In the transformable device according to an embodiment of the present disclosure, performance of the electrodes is suppressed from decreasing in spite of repeated operating and a life of the transformable device can be increased as compared with a case of forming electrodes outside an electro-active layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority of Korean Patent Application Nos.2015-0084577 filed on Jun. 15, 2015 and 2014-0175855 filed on Dec. 9,2014, in the Korean Intellectual Property Office, the disclosures ofwhich are incorporated herein by reference for all purposes as if fullyset forth herein.

BACKGROUND

1. Field of the Invention

The present disclosure relates to a transformable device and a method ofmanufacturing the transformable device. More, particularly, the presentdisclosure relates to a transformable device including electrodestherein, and a method of manufacturing the transformable device.

2. Description of the Related Art

An electro-active polymer (EAP) is a polymer which is transformable byelectrical stimulation, and means a polymer which can be repeatedlyexpanded, contracted, and bent by electrical stimulation. Among variouskinds of electro-active polymers, a ferroelectric polymer and adielectric elastomer are mainly used. For example, the ferroelectricpolymer includes PVDF (Poly VinyliDene Fluoride) and P(VDF)-TrFE(Poly(VinyliDene Fluoride)-trifluoroethylene), and the dielectricelastomer may be based on silicon, urethane, acryl, or the like.

The ferroelectric polymer has advantages of satisfactory flexibility andsatisfactory permittivity, but has a significant problem in opticalproperties such as light transmissivity. Thus, it is difficult to usethe ferroelectric polymer on the whole face of a display device.Meanwhile, the dielectric elastomer has satisfactory transmissivity, buta driving voltage thereof is high. Thus, there is a problem that it isdifficult to use, as it is, the dielectric elastomer in a display devicewith a relatively low driving voltage such as a mobile device.

However, the dielectric elastomer of the electro-active polymersgenerally has flexibility and elasticity by which a shape thereof isvariously transformable. Accordingly, fields in which dielectricelastomers can be utilized has been recently studied with a flexibledisplay device which has been actively developed. For convenience ofdescription, hereinafter, it is assumed that the dielectric elastomer isused as the electro-active polymer.

When an electric field is applied to an electro-active layer throughelectrodes disposed on both of an upper face and a lower face of theelectro-active layer consisting of electro-active polymers, polarizationoccurs inside the electro-active layer. Positive charges and negativecharges are accumulated on the electrodes disposed at an upper portionand a lower portion of the electro-active layer due to suchpolarization, respectively, and Maxwell Stress is applied to theelectro-active layer by electrostatic attractive force (coulombic force)generated among the accumulated charges. A formula representing amagnitude of Maxwell Stress is as follows.

$\begin{matrix}{{{Maxwell}\mspace{14mu} {{Stress}(P)}} = {{ɛ_{r}ɛ_{o}E^{2}} = {ɛ_{r}{ɛ_{o}\left( \frac{V}{t} \right)}^{2}}}} & \left\lbrack {{Math}\mspace{14mu} 1} \right\rbrack\end{matrix}$

Herein, Maxwell Stress means force of an electro-active layer to becontracted in a thickness direction and to be expanded in a lengthdirection by electrostatic attractive force of charges. Due to aproperty of an electro-active layer transformed by Maxwell Stress, theelectro-active layer is in the limelight as a new material constitutingan electro-active layer of a transformable device.

Referring to Math 1, the magnitude P of Maxwell Stress is proportionalto magnitudes of permittivity ∈_(r), electric field E, and voltage V ofthe electro-active layer. When the magnitude of Maxwell Stress getslarger, the electro-active layer has more displacement or is furthertransformed. Accordingly, in order to increase the displacement or thedegree of transformation of the transformable device, the magnitude ofMaxwell Stress has to be increased. Thus, in order to increase MaxwellStress and lower the driving voltage of the transformable device, astudy to raise permittivity of the electro-active layer or to raise aneffective electric field is being conducted.

By flexibility and elasticity of the electro-active layer and MaxwellStress, a method of disposing and forming electrodes in a transformabledevice rises as an important matter. An electrode formed by sputteringthat is a general electrode forming method may be damaged bytransformation at the time of operating a transformable device includingan electro-active layer consisting of electro-active polymers, andperformance of the transformable device is decreased in accordance withrepeated operating of the transformable device. An electro-activepolymer layer may be inserted between support substrates on whichelectrodes are formed by the other method. However, since the supportsubstrates have unsatisfactory flexibility as compared with theelectro-active layer, the displacement of the electro-active layer maybe restricted by the support substrates. Therefore, as an electrodeapplied to a transformable device including an electro-active layerconsisting of electro-active polymers, a soft electrode suitable fortransformation is used.

As such a soft electrode, an electrode manufactured by mixing an elasticbody with carbon conductive grease, carbon black, or carbon nanotube(CNT) was used. Such an electrode may be formed by a printing process,and has problem that a sheet resistance property is not satisfactory anda process is not easy.

Thus, a transformable device and a method of manufacturing thetransformable device are necessary, of which performance is notdecreased in spite of repeated operating, displacement of anelectro-active layer can be maximally secured by Maxwell Stress, and amanufacturing process is easy.

In order to solve the problem of low performance and shortened life ofthe electrodes of the transformable device as described above, theinventors of the present disclosure have invented a new-structuretransformable device and a method of manufacturing the same withelectrodes formed inside an electro-active layer.

An object of the present disclosure is to provide a transformable deviceand a method of manufacturing the same being able to form electrodesinside an electro-active layer by a simple process.

Further, another object of the present disclosure is to provide atransformable device and a method of manufacturing the same capable ofkeeping performance of an electrode in spite of repeated operating andincreasing a life in accordance with forming an electrode inside theelectro-active layer.

Further, still another object of the present disclosure is to provide adisplay device which does not require a separate adhesive layer used toadhere an electrode outside a transformable device and a separateshielding layer in accordance with forming an electrode inside thetransformable device and which is thereby thin.

Objects of the present disclosure are not limited to the objectsdescribed above, and other objects which are not mentioned above can beclearly understood by a person skilled in the art from the followingdescription.

SUMMARY OF THE INVENTION

In order to solve the problems described above, a transformable deviceaccording to an embodiment of the present disclosure is provided. Thetransformable device includes an electro-active layer. The firstelectrode is disposed inside the electro-active layer. The secondelectrode is disposed inside the electro-active layer, and is disposedon the first electrode a distance from the first electrode. In thetransformable device according to an embodiment of the presentdisclosure, performance of the electrodes is suppressed from decreasingin spite of repeated operating, and a life of the transformable devicecan be increased as compared with a case of forming electrodes outsidean electro-active layer.

According to another aspect of the present invention, the electro-activelayer is formed to surround all of the first electrode and the secondelectrode.

According to another aspect of the present invention, at least one ofthe first electrode and the second electrode is formed by precipitationof a conductive material. In this case the first and second electrodescan be embedded into the material of the electro-active layer, includingnatural precipitation, in which conductive material sediments under theinfluence of gravity within the material of the electro-active layerwhich is still at least partially liquid, and chemical precipitation bymeans of an additional precipitant that reacts chemically with theconductive material. According to another aspect of the presentdisclosure, the electro-active layer includes an electro-active polymer.

According to an exemplary embodiment of the present invention, theelectro-active layer includes an elastomer, in particular a dielectricelastomer.

According to still another aspect of the present disclosure, theelectro-active layer further includes impurities, the impuritiesincluding at least one of a conductive material, a precipitant, and acompound of the conductive material and the precipitant, and a hardener.

According to still another aspect of the present disclosure, aconcentration of the impurities in the electro-active layer gets higheras getting closer to the first electrode and the second electrode.

According to still another aspect of the present disclosure, theelectro-active layer is disposed to surround the first electrode and thesecond electrode.

According to still another aspect of the present disclosure, the firstelectrode and the second electrode are formed within a range along thethickness direction of the electro-active layer in which theconcentration of the impurities in the electro-active layer is higherthan a specific concentration.

According to still another aspect of the present disclosure, a thicknessof the electro-active layer is 50 μm to 400 μm. According to oneexemplary embodiment, the thickness of the electro-active layer is 100μm to 300 μm. The thickness should be selected in consideration of powerconsumption and driving voltage necessary to operate the transformabledevice. If the thickness is excessive, a high driving voltage isrequired to generate Maxwell stress necessary to normally operate thetransformable device, and the power consumption is increased. However,if the thickness is too small, sufficient voltage necessary to normallyoperate the transformable device cannot be applied.

According to still another aspect of the present disclosure, at leastone of a thickness between a lower face of the first electrode and alower face of the electro-active layer and a thickness between an upperface of the second electrode and an upper face of the electro-activelayer is 0.1 μm to 10 μm.

According another exemplary embodiment of the present invention, atleast one of the thickness between the lower face of the first electrodeand the lower face of the electro-active layer and the thickness betweenthe upper face of the second electrode and the upper face of theelectro-active layer is proportional to the thickness of theelectro-active layer.

In order to solve the problem described above, a display deviceaccording to another embodiment of the present disclosure is provided.The display device according to the present invention includes a displaypanel and a transformable device as described above. The transformabledevice is disposed under the display panel. The transformable devicecomprises an electro-active layer and electrodes that are inserted intothe electro-active layer. As the transformable device is transformed,the display device is also transformed to various forms, and the displaydevice can provide outputs which are transformed to various forms.

According to another aspect of the present disclosure, the display panelhas a flexible substrate.

According to still another aspect of the present disclosure, the displaydevice further includes a lower cover that is disposed under thetransformable device, and an upper cover that is disposed on thetransformable device, wherein the lower cover and the upper coverconsists of a material having flexibility.

The display device of the above kind may be one of the following: asmartphone; a watch; an electronic newspaper; a curtain.

According to still another aspect of the present disclosure, the displaydevice of the above kind is one of the following: a smartphone; a watch;an electronic newspaper; a curtain.

The present disclosure is further related to a method for manufacturinga transformable device of the above kind comprising the steps of:injecting conductive material to a first electro-active layer materialand a second electro-active layer material; precipitating the conductivematerial to form a first electro-active layer and a secondelectro-active layer with first and second electrodes disposed insidethe first and second electro-active layers, respectively, and hardeningthe first electro-active layer and the second electro-active layer; andjoining the first electro-active layer and the second electro-activelayer to each other.

In this method, the first and second electrodes are formed individuallyin the respective first and second electro-active layers. By controllingthe precipitation of the conductive material and the hardening of thematerial of the first and second electro-active layers, a variation ofconcentration of impurities, including, for example, the conductivematerial, the precipitant, and the hardener can be varied within therespective electro-active layer, as well as the forming of the first andsecond electrodes. When the individual first and second electro-activelayers are hardened, they can be joined to each other without the needof any adhesive layer between them.

According to one embodiment, the first and second electro-active layerare joined to each other by heat.

According to another embodiment of the present invention, pressure isapplied to the first and second electro-active layers which are heated,thereby completely joining them. An interface between the first andsecond electro-active layer disappears in this process, and onelectro-active layer is formed.

According to one embodiment of the present invention, the precipitationof the conductive material is a natural precipitation, in which theconductive material is precipitated in the electro-active layer materialwith liquidity by gravity. This natural precipitation is a sedimentationin which the precipitant is deposited.

According to another embodiment of the present invention, theprecipitation is a chemical precipitation in which the conductivematerial is precipitated in the electro-active layer material withliquidity by a chemical reaction with a precipitant.

According to different embodiments of the present invention, thehardening of the first and second electro-active layer materials can beperformed by natural hardening, in which that the electro-active layermaterial is hardened at a normal temperature, by chemical hardening,meaning that the electro-active layer material is hardened in a chemicalreaction, hardening by heat, i.e. at a temperature higher than a normaltemperature, or hardening by light, for example, by ultraviolet rays(UV).

According to another embodiment of the method according to the presentinvention, the method comprises a process of injecting a precipitantand/or a hardener to the first electro-active layer material and thesecond electro-active layer material.

According to still another preferred embodiment of the presentinvention, the process of injecting a precipitant to the firstelectro-active layer material and the second electro-active layermaterial and the process of injecting a hardener to the firstelectro-active layer material and the second electro-active layermaterial are simultaneously performed.

According to another preferred embodiment of the present invention thespeed of hardening of the first electro-active layer material and thesecond electro-active layer material is controlled by setting a ratio ofthe respective electro-active layer material and the hardener. In thisembodiment, the concentration of impurities, including the conductivematerial, the precipitant and the hardener in the respectiveelectro-active layer can be controlled. With a variation ofconcentration of the impurities, the permittivity of the respectiveelectro-active layer can be varied.

Details of other embodiments are included in the detailed descriptionand the drawings.

According to the present disclosure, it is possible to provide thetransformable device in which the electrodes for applying voltage to theelectro-active layer can be easily formed inside the electro-activelayer, in which performance of the electrodes can be kept for a longtime in spite of repeated operating.

In addition, it is possible to provide the transformable device in whichthe electrodes can be formed inside the electro-active layer within ashort processing time without an expensive electrode forming equipmentfor forming the electrodes.

Moreover, since a separate adhesive layer and shielding layer are notnecessary when the electrodes are inserted into the transformable deviceto provide the transformable device with the electrodes, it is possibleto provide the display device which has a small thickness and isadvantageous in being thin.

Advantages according to the present disclosure are not limited to thedescription exemplified above, and more various advantages are includedin the specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective diagram illustrating a transformabledevice according to an embodiment of the present disclosure.

FIG. 2A to FIG. 2C are schematic cross-sectional views of atransformable device according to an embodiment of the presentdisclosure and a graph illustrating a concentration of a conductivematerial with respect to a height of an electro-active layer.

FIG. 3 is a flowchart illustrating a method of manufacturing atransformable device according to an embodiment of the presentdisclosure.

FIG. 4A to FIG. 4D are perspective views illustrating processes of amethod of manufacturing a transformable device according to anembodiment of the present disclosure.

FIG. 5 is a schematic cross-sectional view illustrating a transformabledevice according to another embodiment of the present disclosure.

FIG. 6 is an exploded perspective view illustrating a display deviceincluding a transformable device according to an embodiment of thepresent disclosure.

FIG. 7 is an exemplary state diagram illustrating varioustransformations of a display device including a transformable deviceaccording to an embodiment of the present disclosure.

FIG. 8 is an exemplary diagram illustrating an electronic newspaperincluding a transformable device according to an embodiment of thepresent disclosure.

FIG. 9 is an exemplary diagram illustrating a watch including atransformable device according to an embodiment of the presentdisclosure.

FIG. 10 is an exemplary diagram illustrating a curtain including atransformable device according to an embodiment of the presentdisclosure.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

Advantages and features of the present disclosure and method ofachieving them will be clarified with reference to the embodimentsdescribed below in detail with the accompanying drawings. However, thepresent disclosure is not limited to the embodiments described below,and will be embodied in various forms. The embodiments make the presentdisclosure complete, and is provided to allow a person skilled in theart to completely know the scope of the present disclosure, but isdefined only by the scope of Claims.

Shapes, sizes, ratios, angles, the number of components, and the likedisclosed in the drawings for describing the embodiments of the presentdisclosure are exemplary, and the present disclosure is not limited tothe illustration. In addition, in the description of the presentdisclosure, when it is determined that specific description about therelated known technique may unnecessarily blur the gist of the presentdisclosure, detailed description thereof is omitted. When ‘include’,‘have’, ‘comprise’, and the like mentioned in the specification areused, other parts may be added unless ‘only’ is used. A constituentelement is expressed by a singular form, it includes a plurality formunless there is specific description.

In analyzing constituent elements, they include an error range even whenthere is no separate description.

In description of positional relations, when a positional relationbetween two parts is described with, for example, ‘on’, ‘at an upperportion’, ‘under’, ‘at a lower portion’, ‘near’, and the like, one ormore other parts may be positioned between two parts unless ‘right’ or‘directly’ is used.

Description that a device or a layer is on another device or layerincludes all cases where another layer or another device is interposedright on another device or in between.

Although the first, the second, or the like are used to describe variousconstituent elements, the constituent elements are not limited by theseterms. These terms are used merely to distinguish one constituentelement from the other constituent element. Accordingly, the firstconstituent element mentioned hereinafter may be the second constituentelement within the technical spirit of the present disclosure.

Throughout the specification, the same reference numerals and signsdenote the same constituent elements.

A size and a thickness of each configuration illustrated in the drawingsare shown for convenience of description, but the present disclosure isnot necessarily limited to the size and the thickness of the illustratedconfiguration.

Features of various embodiments of the present disclosure can bepartially or entirely coupled or combined with each other, and cantechnically variously interlocked or operated as can be sufficientlyunderstood by a person skilled in the art, and the embodiments may beembodied independently from each other, and may be embodied together incooperation with each other.

Hereinafter, various embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is a schematic perspective view illustrating a transformabledevice according to an embodiment of the present disclosure. Referringto FIG. 1, a transformable device 100 includes an electro-active layer110, a first electrode 121, and a second electrode 122.

Referring to FIG. 1, the electro-active layer 110 includeselectro-active polymers. Specifically, the electro-active layer 110consists of dielectric elastomers. For example, the electro-active layer110 may consists of dielectric elastomer based on silicon, urethane,acryl, or the like.

The first electrode 121 is an electrode that is disposed at a lowerportion of the transformable device 100. Specifically, the firstelectrode 121 is disposed at the lower portion of the electro-activelayer 110 inside the electro-active layer 110. For example, the firstelectrode 121 may be disposed separately from a lower face of theelectro-active layer 110 inside the electro-active layer 110 asillustrated in FIG. 1, and the first electrode 121 may be disposed tocome in contact with the lower face of the electro-active layer 110inside the electro-active layer 110 although not illustrated.

The second electrode 122 is an electrode that is disposed at an upperportion of the transformable device 100. The second electrode 122 isdisposed at the upper portion of the electro-active layer 110 inside theelectro-active layer 110 in a vertical distance from the first electrode121. For example, the second electrode 122 may be disposed separatelyfrom an upper face of the electro-active layer 110 inside theelectro-active layer 110 as illustrated in FIG. 1, and the secondelectrode 122 may be disposed to come in contact with the upper face ofthe electro-active layer 110 inside the electro-active layer 110although not illustrated.

The first electrode 121 and the second electrode 122 may be made of thesame material. Specifically, the first electrode 121 and the secondelectrode 122 include a conductive material. For example, the firstelectrode 121 and the second electrode 122 may be made of variousconductive materials such as metal powder, carbon nanotube (CNT),Ag-Nanowire (Ag-NW), or conductive polymer. In some embodiments, thefirst electrode 121 and the second electrode 122 may further includeimpurities other than conductive materials. In this case, the impuritiesmay be a precipitant or a compound of a conductive material and aprecipitant.

Although not illustrated in FIG. 1, the electro-active layer 110 mayfurther include impurities other than the electro-active polymer.Specifically, the impurities may be at least one of the same materialsas the conductive material constituting the first electrode 121 and thesecond electrode 122, the precipitant, and the compound of theprecipitant and the conductive material.

When there are impurities in the electro-active layer 110, aconcentration of the impurities in the electro-active layer 110increases closer to the first electrode 121 and the second electrode122. In other words, the concentration of the impurities is highestaround the first electrode 121 and the second electrode 122, and islowest at the center of the electro-active layer 110 that is anintermediate portion between the first electrode 121 and the secondelectrode 122.

The concentration of the impurities in the electro-active layer 110 hasan influence on a magnitude of Maxwell Stress applied to theelectro-active layer 110. Maxwell Stress is proportional to permittivityof the electro-active layer 110, and the permittivity may be raised bythe impurities in the electro-active layer 110. Specifically, when thereare impurities in the electro-active layer 110, the permittivity of theelectro-active layer 110 is raised, and thus, Maxwell Stress applied tothe electro-active layer 110 may be increased.

The first electrode 121 and the second electrode 122 are softelectrodes. In other words, the first electrode 121 and the secondelectrode 122 may have flexibility to transform a shape in theelectro-active layer 110 made of elastomers having flexibility.Accordingly, the first electrode 121 and the second electrode 122 areinserted into the electro-active layer 110. Thus, cracks do not occurand performance of the electrodes is not lowered even when the shape ofthe electro-active layer 110 is transformed.

The electro-active layer 110 is transformed by an electric fieldgenerated by charges supplied to the first electrode 121 and the secondelectrode 122, and the transformable device 100 is thereby transformed.Specifically, a direction and a shape of transformation of thetransformable device 100 may be varied according to polarity of thecharges supplied to the first electrode 121 and the second electrode122. Hereinafter, a procedure of transforming the electro-active layer110 by the first electrode 121 and the second electrode 122 will bedescribed in detail.

The first electrode 121 supplies charges to the lower portion of theelectro-active layer 110. The second electrode 122 supplies charges tothe upper portion of the electro-active layer 110. Accordingly, anelectric field is formed between the first electrode 121 and the secondelectrode 122. In this case, electrical properties of the chargessupplied to the first electrode 121 and the second electrode 122 may beopposite to each other. In other words, when positive charges aresupplied to the first electrode 121, negative charges are supplied tothe second electrode 122, and when negative charges are supplied to thefirst electrode 121, positive charges are supplied to the secondelectrode 122. In this case, when the electrical property of the chargessupplied to the first electrode 121 and the electrical property of thecharges supplied to the second electrode 122 are changed to be oppositeto each other, the direction of the electrical field is also changed. Inother words, voltage applied to the electro-active layer 110 between thefirst electrode 121 and the second electrode 122 may bealternating-current (AC) voltage, and an electric field based on thealternating-current voltage is formed between the first electrode 121and the second electrode 122. In some embodiments, positive charges ornegative charges are supplied to any one of the first electrode 121 andthe second electrode 122, and the other may be grounded.

Accordingly, the electric field formed between the first electrode 121and the second electrode 122 causes polarization in the electro-activelayer 110 between the first electrode 121 and the second electrode 122,and the electro-active layer 110 subjected to Maxwell Stress by theelectrostatic attractive force based on the polarization is transformed.

When the alternating-current voltage is applied between the firstelectrode 121 and the second electrode 122, Maxwell Stress is generatedin the electro-active layer 110 by the electric field between the firstelectrode 121 and the second electrode 122. A degree of transformationof the electro-active layer 110 and the transformable device 100 isvaried according to amplitude of such alternating-current voltageapplied between the first electrode 121 and the second electrode 122.Specifically, when the amplitude of the alternating-current voltageapplied between the first electrode 121 and the second electrode 122 isincreased, the magnitude of Maxwell Stress is increased in proportionalto the square of the amplitude of the alternating-current voltage.Accordingly, when the amplitude of the alternating-current voltageapplied between the first electrode 121 and the second electrode 122 isincreased, the magnitude of Maxwell Stress is increased, and the shapesof the electro-active layer 110 and the transformable device 100 aregreatly transformed.

In addition, a transformation speed of the electro-active layer 110 andthe transformable device 100 is changed according to a frequency of thealternating-current voltage applied between the first electrode 121 andthe second electrode 122. Specifically, when the frequency of thealternating-current voltage applied between the first electrode 121 andthe second electrode 122 is raised, polarity of the alternating-currentvoltage applied between the first electrode 121 and the second electrode122 is rapidly changed. Accordingly, the direction of Maxwell Stressapplied to the electro-active 110 and the transformable device 100 israpidly changed, and the direction of transformation of theelectro-active 110 and the transformable device 100 is also rapidlychanged.

In the transformable device 100 according to an embodiment of thepresent disclosure, the first electrode 121 and the second electrode 122capable of keeping performance for a long period in spite of repeatedoperating are disposed inside the electro-active layer 110.Specifically, the first electrode 121 is inserted into the lower portionin the electro-active layer 110, the second electrode 122 is insertedinto the upper portion in the electro-active layer 110, and thus theelectric field is formed in the electro-active layer 110 by the chargessupplied from the first electrode 121 and the second electrode 122.However, when a first electrode and a second electrode are formed in amanner of coating or printing soft electrodes on an outer face of anelectro-active layer, the soft electrodes are broken or damaged due torepeated operating of a transformable device. Accordingly, the softelectrodes do not serve as electrodes, and the transformable devicecannot also operate. On the contrary, in the transformable device 100according to an embodiment of the present disclosure, the firstelectrode 121 and the second electrode 122 are inserted into theelectro-active layer 110, and are made of a material suitable fortransformation, and thus a damage of the first electrode 121 and thesecond electrode 122 can be minimized in spite of repeated operating ofthe transformable device 100.

In addition, when the electro-active layer 110 of the transformabledevice 100 according to an embodiment of the present disclosure includesimpurities, the magnitude of Maxwell Stress is increased by theimpurities in the electro-active layer 110. Specifically, there may beimpurities other than electro-active polymers in the electro-activelayer 110 between the first electrode 121 and the second electrode 122,the electro-active polymers including the impurities have higherpermittivity than that of dielectric elastomers which do not include theimpurities. Accordingly, since the electro-active layer 110 includingthe impurities has higher permittivity than that of the electro-activelayer which does not include the impurities, the magnitude of MaxwellStress proportional to permittivity is also increased.

Hereinafter, it will be described in detail that a driving voltage ofthe transformable device 100 is lowered in accordance with disposing thefirst electrode and the second electrode in the electro-active layer 110with reference to FIG. 2A to FIG. 2C together.

FIG. 2A to FIG. 2C are schematic cross-sectional views of atransformable device according to an embodiment of the presentdisclosure and a graph illustrating a concentration of a conductivematerial with respect to a height of an electro-active layer in thecross-sectional view. Specifically, FIG. 2A is a schematiccross-sectional view of the transformable device according to anembodiment of the present disclosure, FIG. 2B is a cross-sectional viewobtained by enlarging a part (X) of the transformable device in FIG. 2A,and FIG. 2C is a graph about a concentration of a conductive materialaccording to a height in the cross section of the transformable deviceillustrated in FIG. 2B. Since FIG. 2A and FIG. 2B are cross-sectionalviews of the transformable device 100 illustrated in FIG. 1, the samedescription is not repeated.

Referring to FIG. 2A, the first electrode 121 is disposed away from thelower face of the electro-active layer 110, and the second electrode 122is disposed away from the upper face of the electro-active layer 110.Accordingly, the electro-active layer 110 is formed to surround all ofthe first electrode 121 and the second electrode 122. In other words,the first electrode 121 and the second electrode 122 are inserted intothe electro-active layer 110. Specifically, the conductive materialinjected to the electro-active layer material is precipitated to be awayfrom the lower face of the electro-active layer, thereby forming theelectrodes. For example, the conductive material is injected to thefirst electro-active layer material, and the injected conductivematerial is precipitated to be away from the lower face of the firstelectro-active layer, thereby forming the first electrode 121, and theconductive material is injected to the second electro-active layermaterial, and the injected conductive material is precipitated to beaway from the lower face of the second electro-active layer, therebyforming the second electrode 122. In this case, the first electrode 121and the second electrode 122 may be formed to have an arbitrarythickness by precipitating the conductive material. Accordingly, afterthe first electrode 121 and the second electrode 122 are formed, thetransformable device 100 may be formed by joining the firstelectro-active layer material and the second electro-active layermaterial such that the second electrode 122 is disposed above the firstelectrode 121 as illustrated in FIG. 2A. In other words, as illustratedin FIG. 2A, in the transformable device 100, the first electrode 121 maybe formed away from the lower face of the electro-active layer 110, andthe second electrode 122 may be formed away from the upper face of theelectro-active layer 110. A specific method of manufacturing thetransformable device including the first electrode 121 and the secondelectrode 122 will be described later with reference to FIG. 3 and FIG.4A to FIG. 4D.

As described above, when the electro-active layer 110 is formed underthe first electrode 121 and on the second electrode 122 inside theelectro-active layer 110, a thickness d1 of the electro-active layer 110formed under the first electrode 121 and a thickness d2 of theelectro-active layer 110 formed on the second electrode 122 are smallerthan a thickness d3 of the electro-active layer 110 formed between thefirst electrode 121 and the second electrode 122. In some embodiments,the thickness d1 of the electro-active layer 110 formed under the firstelectrode 121 and the thickness d2 of the electro-active layer 110formed on the second electrode 122 may be different from each other.

Herein, the thickness d of the electro-active layer 110 may be freelyselected by a person skilled in the art considering power consumptionand driving voltage necessary to operate the transformable device 100and considering whether to normally operate as the transformable device100. Preferably, the thickness d of the electro-active layer 110 may be50 μm to 400 μm. More preferably, the thickness d of the electro-activelayer 110 may be 100 μm to 300 μm. Herein, when the thickness d of theelectro-active layer 110 is smaller than 50 μm, sufficient voltagenecessary to normally operate the transformable device 100 cannot beapplied. Accordingly, the transformable device 100 cannot be normallyoperated. In addition, when the thickness d of the electro-active layer110 is larger than 400 μm, a high driving voltage is required togenerate Maxwell Stress necessary to normally operate the transformabledevice, and power consumption may be excessively increased thereby.

The part of the electro-active layer 110 formed under the firstelectrode 121 and the part of the electro-active layer 110 formed on thesecond electrode 122 may serve as shielding layers. In other word, thepart of the electro-active layer 110 formed under the first electrode121 and the part of the electro-active layer 110 formed on the secondelectrode 122 can shield the first electrode 121 and the secondelectrode 122 from contacting with an external conductive material.Accordingly, the first electrode 121 and the second electrode 122 may beconnected to an external power supply line through contact holes of thepart of the electro-active layer 110 formed under the first electrode121 and the part of the electro-active layer 110 formed on the secondelectrode 122.

The thickness d1 of the electro-active layer 110 formed under the firstelectrode 121 and the thickness d2 of the electro-active layer 110formed on the second electrode 122 may be determined suitably to performthe shielding layer function. For example, at least one of the thicknessd1 of the electro-active layer 110 formed under the first electrode 121and the thickness d2 of the electro-active layer 110 formed on thesecond electrode 122 may be 0.1 μm to 10 μm. Herein, when the thicknessd1 of the electro-active layer 110 formed under the first electrode 121and the thickness d2 of the electro-active layer 110 formed on thesecond electrode 122 are smaller than 0.1 μm, the functions as theshielding layers of the electro-active layer 110 formed under the firstelectrode 121 and the electro-active layer 110 formed on the secondelectrode 122 may significantly decreased. When the thickness d1 and thethickness d2 are larger than 10 μm, it may be difficult to connect thefirst electrode 121 and the second electrode 122 to the external powersupply line through the contact holes. In this case, the electro-activelayer 110 having the relation in thickness described above can be formedby adjusting a concentration and a specific gravity of the conductivematerial injected to the electro-active layer 110 and adjusting whetherto add a precipitant.

In some embodiments, when the thickness d of the electro-active layer110 is 300 μm and when the thickness d1 of the electro-active layer 110formed under the first electrode 121 and the thickness d2 of theelectro-active layer 110 formed on the second electrode 122 are severalμm to 10 μm, the thickness d3 of the electro-active layer 110 formedbetween the first electrode 121 and the second electrode 122 is formedwith about 280 μm to 290 μm.

The thickness d3 of the electro-active layer 110 between the firstelectrode 121 and the second electrode 122 has an influence on themagnitude of Maxwell Stress applied to the electro-active layer 110.Maxwell Stress is proportional to a magnitude of an effective electricfield, and the magnitude of the effective electric field between thefirst electrode 121 and the second electrode 122 is increased as thedistance between the first electrode 121 and the second electrode 122gets smaller. According to the decrease of the thickness d3 of theelectro-active layer 110 formed between the first electrode 121 and thesecond electrode 122 by decreasing the distance between the firstelectrode 121 and the second electrode 122, the magnitude of theeffective electric field applied to the electro-active layer 110 betweenthe first electrode 121 and the second electrode 122 is increased.Accordingly, in order to increase the magnitude of the effectiveelectric field while minimizing the amplitude of the alternating-currentvoltage applied between the first electrode 121 and the second electrode122, the first electrode 121 and the second electrode 122 are disposedin the electro-active layer 110 to make the distance between the firstelectrode 121 and the second electrode 122 narrow. As compared with acase where the first electrode 121 and the second electrode 122 aredisposed on the upper face and the lower face of the electro-activelayer 110, respectively, that is, a case where the first electrode 121and the second electrode 122 are away by the thickness d of theelectro-active layer 110, Maxwell Stress applied to the electro-activelayer 110 may be increased, and the transformable device 100 can beoperated only by the alternating-current voltage with small amplitude.

Referring to FIG. 2B and FIG. 2C, the concentration of the conductivematerial is gradually decreased in a direction from the lower face ofthe first electrode 121 to the center of the electro-active layer 110.Specifically, it is determined that a direction from the lower face ofthe electro-active layer 110 toward the upper face of the electro-activelayer 110 is a thickness direction Td of the electro-active layer 110,the concentration N of the conductive material is gradually decreased asgetting close to the center of the electro-active layer 110 along thethickness direction Td of the electro-active layer 110 from the firstelectrode 121. In addition, there may be no conductive material in theelectro-active layer 110 between the lower face of the electro-activelayer 110 and the lower face of the first electrode 121. In other words,in order for the conductive material to substantially serve as anelectrode, the conductive material is precipitated to be away from thelower face of the electro-active layer 110 by an arbitrary thickness,and is precipitated corresponding to the thickness of the firstelectrode 121, thereby configuring the first electrode 121.

When the concentration of the conductive material is equal to or lowerthan a specific concentration NO (percolation threshold) while theconcentration N of the conductive material is decreased along thethickness direction Td of the electro-active layer 110, the conductivematerial cannot serves an electrode. In other words, as proceeding inthe thickness direction Td of the electro-active layer 110 from theupper face of the first electrode 121 formed by precipitation, theconcentration N of the conductive material is decreased to be a theconcentration NO or lower capable of serving as an electrode. Therefore,the conductive material existing between the upper face of the firstelectrode 121 and the center of the electro-active layer 110 does notsubstantially constitute the electrode. Similarly, as illustrated inFIG. 2A, as getting close to the center of the electro-active layer 110from the lower face of the second electrode 122 formed by precipitation,the concentration N of the conductive material is decreased to be a theconcentration NO or lower capable of serving as an electrode. Therefore,the conductive material existing between the lower face of the secondelectrode 122 and the center of the electro-active layer 110 does notsubstantially constitute the electrode.

Accordingly, although there is the conductive material in theelectro-active layer 110 between the first electrode 121 and the secondelectrode 122, the conductive material existing in the electro-activelayer 110 between the first electrode 121 and the second electrode 122may not serve as an electrode. However, the conductive material existingin the electro-active layer 110 between the first electrode 121 and thesecond electrode 122 serves as a dopant of increasing Maxwell Stress byincreasing permittivity of the electro-active layer 110. Accordingly,Maxwell Stress acting on the electro-active layer 110 is increased andthe driving voltage for generating the same Maxwell Stress may bedecreased.

In the transformable device 100 according to an embodiment of thepresent disclosure, the first electrode 121 and the second electrode 122are disposed in the electro-active layer 110, and the magnitude ofMaxwell Stress is increased. Specifically, since the first electrode 121and the second electrode 122 are disposed in the electro-active layer110, the distance between the first electrode 121 and the secondelectrode 122 is decreased as compared with a case where electrodes aredisposed outside the electro-active layer 110. Accordingly, themagnitude of the effective electric field between the first electrode121 and the second electrode 122 is increased, and the magnitude ofMaxwell Stress proportional to the magnitude of the effective electricfield is also increased.

FIG. 3 is a flowchart illustrating a method of manufacturing atransformable device according to an embodiment of the presentdisclosure. FIG. 4A to FIG. 4D are perspective views illustratingprocesses of a method of manufacturing a transformable device accordingto an embodiment of the present disclosure. FIG. 4A to FIG. 4D areperspective views illustrating processes of a method of manufacturingthe transformable device illustrated in FIG. 1, and the constituentelements described with reference to FIG. 1 are not repeatedlydescribed.

First, the conductive material is injected to the first electro-activelayer material and the second electro-active layer material (S31).

Referring to FIG. 4A, the conductive material is injected to the firstelectro-active layer material 491 and the second electro-active layermaterial 492. In this case, the first electro-active layer material 491and the second electro-active layer material 492 include electro-activepolymers, and are in a liquid state or a semi-liquid state. In otherwords, the first electro-active layer material 491 and the secondelectro-active layer material 492 are materials with liquidity, and arein a state where a conductive material can be injected. In addition, aprecipitant may be further injected to the first electro-active layermaterial 491 and the second electro-active layer material 492, and ahardener may be further injected to the first electro-active layermaterial 491 and the second electro-active layer material 492.

Herein, the conductive material includes a material with conductivityindependently in the first electro-active layer material 491 and thesecond electro-active layer material 492. In addition, the conductivematerial may include a material with conductivity through a chemicalreaction with a precipitant. In other words, the conductive materialincludes both of a material itself with conductivity, and a materialitself having no conductivity but having conductivity by reacting with aprecipitant. For example, the conductive material may be metal powder,carbon nanotube (CNT), Ag-Nanowire (Ag-NW), or conductive polymer.

The precipitant is a material which chemically reacts with a conductivematerial to precipitate the conductive material. Accordingly, theprecipitant may be converted into a conductive precipitate by causing aprecipitation reaction with the conductive material. For example, theprecipitant may be a precipitant used in a sewage treatment plant.

Herein, the hardener is a material which hardens the firstelectro-active layer material 491 and the second electro-active layermaterial 492 in a liquid state with liquidity or a semi-liquid stateinto a solid state. A function of the hardener will be described laterwith reference to FIG. 4B.

Subsequently, the conductive material is precipitated to form the firstelectro-active layer and the second electro-active layer (S32). Herein,the electrodes are formed while the conductive material is precipitateddownward in the electro-active layer and the first electro-active layermaterial 491 and the second electro-active layer material 492 arehardened. In other words, in the process of forming the electro-activelayer, a process of precipitating the conductive material downward inthe electro-active layer and a process of hardening the electro-activelayer may be simultaneously performed. However, as the electro-activelayer is hardened at a high speed, a ratio of the precipitatedconductive material of the injected conductive material in theelectro-active layer may be lowered. Accordingly, when the hardeningspeed of the electro-active layer is high, an impurity concentration inthe electro-active layer may be increased.

The conductive material is precipitated in the first electro-activelayer material 491 to form the first electrode 121. Specifically, theconductive material may be naturally precipitated in the firstelectro-active layer material 491 by sedimentation. In this case, thenatural precipitation means that the conductive material is sedimentedin the first electro-active layer material 491 with liquidity bygravity. For example, when the first electro-active layer material 491including the conductive material is left for 24 hours or more, theconductive material is naturally precipitated by gravity.

In addition, the conductive material may be chemically precipitated inthe first electro-active layer material 491 by a precipitant. In thiscase, the chemical precipitation means that the conductive material isprecipitated in the first electro-active layer material 491 withliquidity by a chemical reaction with the precipitant. For example, theconductive material may be changed to a new chemical precipitate withconductivity through chemical coupling with a precipitant, and the newchemical precipitate is disposed under the first electro-active layermaterial 491.

While the first electro-active material 491 is hardened, liquiditythereof may be decreased. Specifically, the first electro-active layer411 may be naturally hardened. In this case, the natural hardening meansthat the first electro-active layer material 491 is hardened at a normaltemperature.

In addition, the first electro-active layer material 491 may bechemically hardened by a hardener. In this case, the chemical hardeningmeans that the first electro-active layer material 491 is hardened by achemical reaction, and a hardening speed may be varied according ahardener. Specifically, a speed of hardening the first electro-activelayer material 491 may be varied according to a ratio of the firstelectro-active layer material 491 and the hardener. For example, whenthe ratio of the first electro-active layer material 491 and thehardener is increased from 10:1 to 10:3, the hardening speed is raised.

In addition, the first electro-active layer material 491 may be hardenedby heat. Specifically, the first electro-active layer material 491 maybe hardened at a temperature higher than a normal temperature, forexample, 90° C. Accordingly, when the first electro-active layermaterial 491 is hardened by heat, the first electro-active layermaterial 491 may be hardened at a speed higher than that of the naturalhardening.

In addition, the first electro-active layer material 491 may be hardenedby light. Specifically, the first electro-active layer material 491 maybe hardened by, for example, ultraviolet rays (UV). Accordingly, whenthe first electro-active layer material 491 is hardened by light, thefirst electro-active layer material 491 may be hardened at a speedhigher than that of the natural hardening.

In such heat hardening and light hardening, a hardener different fromthat of the chemical hardening may be used, a ratio of the firstelectro-active layer material 491 and the hardener may be different fromthat of the chemical hardening.

Accordingly, the liquidity of the first electro-active layer material491 is rapidly decreased by the natural hardening, the chemicalhardening, the heat hardening, and the light hardening, the conductivematerial is rapidly precipitated by the natural precipitation and thechemical precipitation, and the first electrode 121 is thereby formed inthe first electro-active layer 411. In this case, when the hardeningspeed is raised, the first electro-active layer material 491 is rapidlyhardened, and the first electrode 121 is formed in the firstelectro-active layer 411 before all of the conductive material, theprecipitant, and the hardener are precipitated. Accordingly, theconcentration of the impurities including the conductive material, theprecipitant, and the hardener in the first electro-active layer 411 isincreased. As the concentration of the impurities is increased, thepermittivity of the first electro-active layer 411 may be also increasedslightly. When the first electro-active layer 411 is hardened, the firstelectro-active layer 411 is in a state capable of being joined to theother electro-active layer.

The second electrode 122 is formed at the lower portion of the secondelectro-active layer 412 through the same process as the process offorming the first electrode 121 at the lower portion of the firstelectro-active layer 411. However, the process of forming the secondelectrode 122 at the lower portion of the second electro-active layer412 and the process of forming the first electrode 121 at the lowerportion of the first electro-active layer 411 may have difference in aspecific natural precipitation and a natural hardening time or aconfiguration and a ratio of a new chemical precipitate, and the like.In other words, the first electrode 121 and the second electrode 122 maybe formed in the same process, but detailed process conditions in theprocess of forming the first electrode 121 and the second electrode 122may be different.

Subsequently, the first electro-active layer and the secondelectro-active layer are joined to each other (S33).

Referring to FIG. 4C, the first electro-active layer 411 and the secondelectro-active layer 412 are joined to each other. Specifically, thejoining process may be performed after the second electro-active layer412 is turned upside down and is disposed on the first electro-activelayer 411 such that the upper face of the second electro-active layer412 in FIG. 4B comes in contact with the upper face of the firstelectro-active layer 411. In this case, the first electro-active layer411 and the second electro-active layer 412 may be joined to each otherby heat. Specifically, after the upper face of the first electro-activelayer 411 and the upper face of the second electro-active layer 412 aredisposed to come in contact with each other, pressure is applied fromthe lower portion of the first electro-active layer 411 and the upperportion of the second electro-active layer 412, which are heated. Forexample, pressure of about 40 MPa is applied to the first electro-activelayer 411 and the second electro-active layer 412, and the firstelectro-active layer 411 and the second electro-active layer 412 areheated at 150° C. to 200° C., thereby completely joining them.

Specifically, an interface disappears between the upper face of thefirst electro-active layer 411 and the upper face of the secondelectro-active layer 412 by the heat and pressure applied to the firstelectro-active layer 411 and the second electro-active layer 412, andthus one electro-active layer 110 may be formed. Accordingly, thetransformable device 100 is formed in which the first electrode 121 isdisposed at the lower portion and the second electrode 122 is disposedat the upper portion in one electro-active layer 110.

Meanwhile, a part of the electro-active layer 110 may be removed toconnect the first electrode 121 and the second electrode 122 to anexternal power source. Specifically, a part of the electro-active layerformed under the first electrode 121 or on the side thereof, or a partof the electro-active layer 110 formed on the second electrode 122 or onthe side thereof may be removed. In this case, the part of theelectro-active layer 110 may be removed by silicon etchant. A wire maybe connected to come in contact with the first electrode 121 or thesecond electrode 122 through the removed part of the electro-activelayer 110, and power is supplied to the transformable device 100 throughthe wire connected to the first electrode 121 or the second electrode122.

In the method of manufacturing the transformable device according to anembodiment of the present disclosure, the conductive material isprecipitated in the electro-active layer to easily form the electrodes.Specifically, the conductive material is precipitated in theelectro-active layer to form the soft electrodes. In other words, anexpensive separate equipment such as a sputtering equipment to form theelectrodes at the upper portion or the lower portion of theelectro-active layer is not necessary, and the electro-active layerincluding the electrodes therein can be simply and easily formed in bulkonly by natural precipitation based on gravity and chemicalprecipitation based on a precipitant.

In addition, in the method of manufacturing the transformable deviceaccording to another embodiment of the present disclosure, the pluralityof electro-active layers provided therein with electrodes without anyadhesive are heated and pressed to easily form the transformable device100. Specifically, since the electrodes are disposed in theelectro-active layer, the electrodes are not disposed outside theplurality of electro-active layers. Accordingly, an adhesive foradhering between the electro-active layer and the electrode and betweenthe electrodes is not necessary, and the transformable device 100 can beeasily formed by applying heat and pressure to the electro-active layer.

FIG. 5 is a schematic cross-sectional view illustrating a transformabledevice according to another embodiment of the present disclosure. In atransformable device 500 illustrated in FIG. 5, only a position of asecond electrode 522 is changed as compared with the transformabledevice 100 illustrated in FIG. 1 and FIG. 2A, the other configuration issubstantially the same, and the overlapped description is not repeated.

Referring to FIG. 5, a first electrode 521 and a second electrode 522are disposed in the electro-active layer 110. Specifically, the firstelectrode 521 is disposed at the lower portion of the electro-activelayer, and the second electrode 522 is disposed close to the center ofthe electrode active layer 110. For example, the second electrode 522may be disposed at a portion higher than the center of theelectro-active layer 110. In other words, the lower face of the secondelectro-active layer 412 is disposed to come in contact with the upperface of the first electro-active layer 411 without turning upside downthe second electro-active layer 412 such that the upper face of thesecond electro-active layer 412 in FIG. 4B comes in contact with theupper face of the first electro-active layer 421. Accordingly, adistance d4 between the first electrode 521 and the second electrode 522is smaller than the distance d3 between the first electrode 121 and thesecond electrode 122 in the transformable device 100 illustrated in FIG.2A. Accordingly, the distance between the first electrode 521 and thesecond electrode 522 is decreased as compared with the case where thesecond electrode 522 is disposed at the upper portion of theelectro-active layer 110. As the distance between the first electrode521 and the second electrode 522 is decreased, the magnitude of MaxwellStress applied to the electro-active layer 110 is increased.

In the transformable device 500 according to another embodiment of thepresent disclosure, the magnitude of Maxwell Stress is increased betweenthe first electrode 521 and the second electrode 522. Specifically, thefirst electrode 521 is disposed at the lower portion of theelectro-active layer 110 in the electro-active layer 110, and the secondelectrode 522 is disposed at a portion higher than the intermediateportion that is a half of the thickness d of the transformable device100 illustrated in FIG. 2A. In this case, the distance d4 between thefirst electrode 521 and the second electrode 522 is smaller than thedistance d3 between the first electrode 121 and the second electrode 122in the transformable device 100 illustrated in FIG. 2A. Accordingly, thethickness d4 of the electro-active layer formed between the firstelectrode 521 and the second electrode 522 is decreased, the magnitudeof the effective electric field of the electro-active layer formedbetween the first electrode 521 and the second electrode 522 isincreased, and the magnitude of Maxwell Stress may be also increased.

FIG. 6 is a schematic exploded perspective view illustrating a displaydevice including the transformable device according to an embodiment ofthe present disclosure. Referring to FIG. 6, a display device 600includes an upper cover 610, a touch panel 620, a display panel 630, atransformable device 640, and a lower cover 650. Terms like “up”,“down”, “on”, “upper”, “lower”, etc. refer to a usual orientation of adisplay device 600 in use in which the display panel can be watched fromthe upper side, i.e. from the side of the upper cover 610, while thelower cover 650 covers the display device from the opposite side. It isnoted that this terminology shall not restrict the invention to anyorientation of the display device 600 but serves to clarify thearrangement of the different components of the display device 600 withregard to each other.

The upper cover 610 is disposed on the touch panel 620 to cover theupper portions of the touch panel 620, the display panel 630, and thetransformable device 640. The upper cover 610 protects the internalconfigurations in the display device 600 from external impact, foreignmaterials, and moisture. For example, the upper cover 610 may be made ofa material such as plastic which can be formed by heat and hassatisfactory formability, but is not limited thereto. In addition, theupper cover 610 may be made of a material which is transformable withthe change in shape of the transformable device 640. For example, theupper cover 610 may be made of a material such as plastic withflexibility, but is not limited thereto.

The touch panel 620 is disposed on the transformable device 100. Thetouch panel 620 means a panel that senses a touch input of a user to adisplay device 700. For example, an electrostatic capacitance manner, aresistive film manner, an ultrasonic manner, an infrared ray manner, orthe like may be used as the touch panel 620, but preferably, the touchpanel 620 in the electrostatic capacitance manner may be used as thetouch panel 620.

Although not illustrated in FIG. 6, adhesive layers may be used toadhere the display panel 630, the transformable device 640, the touchpanel 620, and the upper cover 610 to one another. The adhesive layersmay be, for example, OCA (optical clear adhesive) or OCR (optical clearresin), but are not limited thereto.

The display panel 630 means a panel in which a display element fordisplaying a video in the display device 600 is disposed. The displaypanel 630 may be, for example, various display panels such as an organiclight emitting display panel, a liquid crystal display panel, and anelectrophoretic display panel. In this case, the display panel 630 maybe an organic light emitting display device. Since the transformabledevice 640 disposed under the display panel 630 may be transformed withflexibility, the organic light emitting display device may be configuredto be also transformed with flexibility. In other words, the organiclight emitting display device is an organic light emitting displaydevice with flexibility, and includes a flexible substrate. The flexibleorganic light emitting display device is transformable in variousdirections and at various angles by force applied from the outside.Hereinafter, for convenience of description, it is assumed that thedisplay panel 630 is configured by the flexible organic light emittingdisplay device.

The transformable device 640 is disposed under the display panel 630.Specifically, the transformable device 640 is disposed under the displaypanel 630. The transformable device 640 may be disposed to come indirect contact with the lower face of the display panel 630, and anadhesive layer may be further disposed between the lower face of thedisplay panel 630 and the upper face of the transformable device 640. Inthis case, the transformable device 640 may be one of the transformabledevice 100 illustrated in FIG. 1 and FIG. 2A and the transformabledevice 500 illustrated in FIG. 5.

In addition, the transformable device 640 may be electrically connectedto the display panel 630. For example, a FPCB (flexible printed circuitboard) disposed in the display panel 630 and the electrodes of thetransformable device 640 may be electrically connected to each other bywiring. The lower cover 650 is disposed under the transformable device640 to cover the lower portions of the touch panel 620, the displaypanel 630, and the transformable device 640. The lower cover 650 may bemade of the same material as that of the upper cover 610. Particularly,the lower cover 650 may be also made of a flexible material to betransformable together with the touch panel 620 and the display panel630 which are transformable in various shapes by the transformabledevice 640. For example, the lower cover 650 may be made of a materialsuch as plastic with flexibility, but is not limited thereto.

As voltage is applied to the transformable device 640, the transformabledevice 640 is transformed. Accordingly, the touch panel 620 and thedisplay panel 630 joined to the transformable device 640 are alsotransformed according to the transformation of the transformable device640, and the display device 600 is also transformed.

In the display device 600 according to an embodiment of the presentdisclosure, the touch panel 620, the display panel 630, and thetransformable device 640 are integrated into one, and the display device600 can be transformed in various shapes by the transformable device640. Specifically, when voltage is applied to the transformable device640, the transformable device 640 is transformed. Accordingly, the touchpanel 620 and the display panel 630 are also transformed togetheraccording to the shape of transformation of the transformable device640. In other words, the entire of the display device 600 can betransformed, and the deformed shape of the display device 600 based onthe transformation of the transformable device 640 will be describedbelow with reference to FIG. 7.

FIG. 7 is an exemplary state diagram illustrating various transformationshapes of the display device including the transformable deviceaccording to an embodiment of the present disclosure. In FIG. 7, forconvenience of description, it is assumed that the display device 700 isa smartphone.

Referring to FIG. 7, a part of the display device 700 can be bent upwardor downward. Specifically, in the display device 700, a transformabledevice is fixed under a display screen 710, and the entire of thetransformable device and the display device 700 is transformed byoperating the transformable device. In other words, a part of thedisplay device 700 may be bent upward or downward according to bendingof a part of the transformable device upward or downward. Herein, as apart of the transformable device is bent upward or downward at apredetermined period, a part of the display device 700 may be also bentupward or downward. In addition, as a state where a part of thetransformable device is bent upward or downward is kept, a state where apart of the display device 700 is bent upward or downward may be kept.

For example, a part of the display device 700 may be bent upward ordownward by an output corresponding to a touch input of a user input tothe display device 700. In other words, when the display device 700receives a message or a voice call is incoming to the display device700, a part of the display device 700 may be bent upward or downward asan output corresponding thereto.

In the display device 700, a bent part, a bending direction, a bendingtime, a period of change in bending direction, and the like may bevariously set through the display device 700. In other words, the changein shape of the display device 700 by the transformable device may bevariously set by a user, and is not limited to the exemplary change inshape described above.

In the display device 700 including the transformable device accordingto an embodiment of the present disclosure, the transformable device istransformed differently according to various inputs. Specifically, thetransformed part, the transforming direction, the continuous time oftransformation, the period of change in transforming direction, and thelike may be set differently for each input applied to the display device700. Accordingly, the display device 700 is transformed in variousshapes by the transformable device, and various kinds of outputs may beprovided for a user.

FIG. 8 is an exemplary diagram of an electronic newspaper including thetransformable device according to an embodiment of the presentdisclosure. Referring to FIG. 8, an electronic news paper 800 includes adisplay panel 810 and a transformable device joined to the lower portionof the display panel 810.

In the electronic newspaper 800 including the transformable deviceaccording to an embodiment of the present disclosure, a feeling similarto reading an actual newspaper made of paper may be provided by thetransformable device. When a signal of turning over a page is inputthrough the display panel 810 of the electronic newspaper 800, thetransformable device at a part to which the signal is input may betransformed. Accordingly, a part of the electronic newspaper 800 istemporarily bent while the transformable device is transformed, and afeeling of turning over a page may be provided like a newspaper made ofpaper.

In addition, when a new article is uploaded and displayed on theelectronic newspaper 800 including the transformable device according toan embodiment of the present disclosure, a part of the electronicnewspaper 800 is transformed to provide the fact that the article isuploaded. For example, when an article having a new headline isuploaded, the transformable device at the article-uploaded part istransformed to immediately display the fact that the article isuploaded.

FIG. 9 is an exemplary diagram illustrating a watch including thetransformable device according to an embodiment of the presentdisclosure. Referring to FIG. 9, a watch 900 includes a display panel910 and a transformable device joined to the lower portion of thedisplay panel 910. For convenience of description, it is assumed thatthe watch 900 is a smart watch.

In the watch 900 including the transformable device according to anembodiment of the present disclosure, various functions of the watch 900may be embodied by the transformable device. General time information isdisplayed through the display panel 910 of the watch 900. In addition,weather, news, and the like may be displayed through the display panel910 of the watch 900. Moreover, the watch 900 may include a simplecalling function, and may determine a heart rate of a user who wears thewatch 900. Herein, in order to let a user know every hour on the hour orknow a designated alarm time, the transformable device in the watch 900may be contracted. Accordingly, time information may be provided bytightening user's wrist. In addition, even when new weather informationor news is displayed, the transformable device in the watch 900 may becontracted, and when a phone call is received, a protrusion portion maybe formed at a part of the display panel 910 of the watch 900, therebyproviding the information. In addition, when a heart rate of a usermeasured through a part of the watch 900 is in a risk level, thetransformable device in the watch 900 may be contracted or changed inshape to provide warning to the user.

FIG. 10 is an exemplary diagram illustrating a curtain including thetransformable device according to an embodiment of the presentdisclosure. Referring to FIG. 10, a curtain 1000 includes a displaypanel 1010 and a transformable device joined to the lower portion of thedisplay panel 1010.

In the curtain 1000 including the transformable device according to anembodiment of the present disclosure, information about externalenvironment may be expressed in various manners by the transformabledevice. Specifically, external weather may be displayed on apredetermined screen through the display panel 1010, and the form of thecurtain 1000 may be changed to express a state of a specific weather.For example, in case of cloudy and windy weather, a cloud may bedisplayed through the display panel 1010 of the curtain 1000, a part ofthe curtain 1000 may be bent, and an area of the bent part may bevaried, according to a direction of wind and a speed of wind by thetransformable device. In other words, a direction in which an actualcurtain is bent or shaken according to the direction of wind may beexpressed by the bending direction of the curtain 1000, and an area ofthe bent part of the curtain 1000 may be increased as the wind getsstronger. Further, when an intensity of light input through a glasswindow is lower than a predetermined intensity, the curtain 1000 may beautomatically rolled up or may be folded left or right.

The embodiments of the present disclosure have been described in moredetail with reference to the accompanying drawings, but the presentdisclosure is not necessarily limited to such embodiments, and may bevariously modified within the scope which does not deviate from thetechnical spirit of the present disclosure. Therefore, the embodimentsdescribed in the present disclosure are not to restrict the technicalspirit of the present disclosure but are to explain it, and the scope ofthe technical spirit of the present disclosure is not restricted by suchembodiments. The protection range of the present disclosure should beunderstood by the following Claims, and it should be understood that allthe technical spirits within the scope equivalent thereto are includedin the right scope of the present disclosure.

What is claimed is:
 1. A transformable device, comprising: anelectro-active layer; a first electrode inside the electro-active layer;and a second electrode inside the electro-active layer on the firstelectrode a distance from the first electrode.
 2. A transformable deviceaccording to claim 1, wherein the electro-active layer is surround allof the first electrode and the second electrode.
 3. A transformabledevice according to claim 1, wherein at least one of the first electrodeand the second electrode includes precipitates of a conductive material.4. A transformable device according to claim 1, wherein theelectro-active layer includes impurities, the impurities including atleast one of a conductive material, a precipitant, a compound of aconductive material and a precipitant, and a hardener.
 5. Atransformable device according to claim 4, wherein a concentration ofthe impurities in the electro-active layer increases closer to the firstelectrode and the second electrode.
 6. A transformable device accordingto claim 3, wherein the first electrode and the second electrode aredisposed within a range along a thickness direction Td of theelectro-active layer in which the concentration of the impurities in theelectro-active layer is higher than a specific concentration N₀.
 7. Atransformable device according to claim 1, wherein a thickness (d) ofthe electro-active layer is 50 μm to 400 μm.
 8. A transformable deviceaccording to claim 1, wherein at least one of a thickness (d1) between alower face of the first electrode and a lower face of the electro-activelayer and a thickness (d2) between an upper face of the second electrodeand an upper face of electro-active layer is 0.1 μm to 10 μm.
 9. Adisplay device, comprising: a display panel; and a transformable devicewherein the transformable device includes: an electro-active layer; afirst electrode inside the electro-active layer; and a second electrodeinside the electro-active layer on the first electrode a distance fromthe first electrode.
 10. The display device according to claim 9,further comprising a touch panel on the display panel.
 11. The displaydevice according to claim 9 further comprising a lower cover under thetransformable device and an upper cover on the transformable device,wherein the lower cover and the upper cover consist of a material havingflexibility.
 12. A method for manufacturing a transformable devicecomprising: injecting conductive material on a first electro-activelayer material and a second electro-active layer material; precipitatingthe conductive material to dispose the first electro-active layer andthe second electro-active layer with first and second electrodes insidethe first and second electro-active layers, respectively, and hardeningthe first electro-active layer and the second electro-active layer; andjoining the first electro-active layer and the second electro-activelayer to each other.
 13. The method of claim 12, comprising a process ofinjecting a precipitant and/or a hardener to the first electro-activelayer material and the second electro-active layer material.
 14. Themethod according to claim 12, wherein the process of injecting aprecipitant on the first electro-active layer material and the secondelectro-active layer material and the process of injecting a hardener tothe first electro-active layer material and the second electro-activelayer material are simultaneously performed.
 15. The method of claim 12,wherein a speed of hardening of the first electro-active layer materialand the second electro-active layer material is controlled by setting aratio of respective electro-active layer material and the hardener.